36,778 research outputs found

    Investigating heuristic evaluation as a methodology for evaluating pedagogical software: An analysis employing three case studies

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    This paper looks specifically at how to develop light weight methods of evaluating pedagogically motivated software. Whilst we value traditional usability testing methods this paper will look at how Heuristic Evaluation can be used as both a driving force of Software Engineering Iterative Refinement and end of project Evaluation. We present three case studies in the area of Pedagogical Software and show how we have used this technique in a variety of ways. The paper presents results and reflections on what we have learned. We conclude with a discussion on how this technique might inform on the latest developments on delivery of distance learning. © 2014 Springer International Publishing

    Overview of Hydra: a concurrent language for synchronous digital circuit design

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    Hydra is a computer hardware description language that integrates several kinds of software tool (simulation, netlist generation and timing analysis) within a single circuit specification. The design language is inherently concurrent, and it offers black box abstraction and general design patterns that simplify the design of circuits with regular structure. Hydra specifications are concise, allowing the complete design of a computer system as a digital circuit within a few pages. This paper discusses the motivations behind Hydra, and illustrates the system with a significant portion of the design of a basic RISC processor

    A novel technique for reducing false positive detections in CAD-CTC

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    Computed tomography colonoscopy (CTC) is an emerging alternative to conventional colonoscopy for colorectal cancer screening. A series of computer assisted diagnosis (CAD) techniques have been developed for use in CTC. Although high levels of accuracy for polyp detection have been reported, the problem of excessive false positive detections still warrants attention. We present a CAD-CTC technique that has been developed specifically to reduce the number of false positive detections without compromising polyp detection accuracy. The technique incorporates a novel intermediate stage that restructures initial polyp candidates so that they conform more closely to the shape of actual polyps. The restructuring process causes false positives to expand to include more false positive characteristics, whereas, actual polyps retain their original polyp-like characteristics. An evaluation of the documented technique demonstrated that it can be successfully applied to the majority of polyp candidates, and that its use can reduce the number of false positive detections by up to 57.8%

    A framework for FPGA functional units in high performance computing

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    FPGAs make it practical to speed up a program by defining hardware functional units that perform calculations faster than can be achieved in software. Specialised digital circuits avoid the overhead of executing sequences of instructions, and they make available the massive parallelism of the components. The FPGA operates as a coprocessor controlled by a conventional computer. An application that combines software with hardware in this way needs an interface between a communications port to the processor and the signals connected to the functional units. We present a framework that supports the design of such systems. The framework consists of a generic controller circuit defined in VHDL that can be configured by the user according to the needs of the functional units and the I/O channel. The controller contains a register file and a pipelined programmable register transfer machine, and it supports the design of both stateless and stateful functional units. Two examples are described: the implementation of a set of basic stateless arithmetic functional units, and the implementation of a stateful algorithm that exploits circuit parallelism

    Salmonella Infection Level in Danish Indoor and Outdoor Pig Production Systems measured by Antbodies in Meat Juice and Faecal Shedding on-farm and at Slaughter

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    The prevalence of Salmonella shedding was compared in 34 organic, conventional outdoor, and indoor pig herds. Individual faecal and meat juice samples from 30-50 pigs per herd were analysed for presence of Salmonella, and Salmonella antibodies, respectively. We found low levels of Salmonella shedding on farm and at slaughter in organic and conventional outdoor herds compared to indoor pigs. Overall 5,5 % of the pigs were seropositive. The serological test result was associated with Salmonella shedding at slaughter in pigs from conventional systems, but not in organic pigs. The duration of transport did not affect the risk of Salmonella shedding

    Using regular expressions to express bowing patterns for string players

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    The study of bowing is critically important for string players. Traditional bowing annotations are a valuable part of orchestral and individual documentation, but they do not help the performer to search a piece for other passages that should be bowed the same way, or to identify alternative bowing styles. We introduce a notation based on regular expressions that describes patterns of notes in the music, as well as the bowing to be applied to the pattern. These expressions support complex bowings, and not just single annotations without musical context. The notation is simpler than general tools for regular expressions used in some software, and is suitable for use by students and musicians. We have developed a music editor that implements the notation and edits documents in Lilypond. The approach has been evaluated by experimenting with the editor on six violin sonatas by Mozart. The experiments demonstrate that the regular expression notation is successful at finding passages and inserting the bowings; that the patterns occur a number of times; and the bowings can be inserted automatically and consistently

    Learning relationships from theory to design

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    This paper attempts to bridge the psychological and anthropological views of situated learning by focusing on the concept of a learning relationship, and by exploiting this concept in our framework for the design of learning technology. We employ Wenger's (1998) concept of communities of practice to give emphasis to social identification as a central aspect of learning, which should crucially influence our thinking about the design of learning environments. We describe learning relationships in terms of form (one‐to‐one, one‐to‐many etc.), nature (explorative, formative and comparative), distance (first‐, second‐order), and context, and we describe a first attempt at an empirical approach to their identification and measurement

    Chemical analysis of Mycenaean pottery from the Menelaion and its vicinity

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    A chemical characterisation of the Mycenaean pottery from the major prehistoric site of the Menelaion in Laconia. The study defines the the lcoal pottery production and identifies the imports from various centres

    Interplay between hydrodynamic and Brownian fluctuations in sedimenting colloidal suspensions

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    We apply a hybrid molecular dynamics and mesoscopic simulation technique to study the steady-state sedimentation of hard sphere particles for Peclet number (Pe) ranging from 0.08 to 12. Hydrodynamic backflow causes a reduction of the average sedimentation velocity relative to the Stokes velocity. We find that this effect is independent of Pe number. Velocity fluctuations show the expected effects of thermal fluctuations at short correlation times. At longer times, nonequilibrium hydrodynamic fluctuations are visible, and their character appears to be independent of the thermal fluctuations. The hydrodynamic fluctuations dominate the diffusive behavior even for modest Pe number, while conversely the short-time fluctuations are dominated by thermal effects for surprisingly large Pe numbers. Inspired by recent experiments, we also study finite sedimentation in a horizontal planar slit. In our simulations distinct lateral patterns emerge, in agreement with observations in the experiments

    Bowing models for string players

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    A bowing is a sequence of bow motions that enable a piece of music to be played on a string instrument with an appropriate interpretation and sound. Traditional notation shows only the bow direction for a few notes. We propose a bowing model, which contains information about the bowings of all the notes, and we show how the bowing model can be represented in software and describe how algorithms can use it to perform several tasks that help the performer. The model, and the algorithms, are suitable both for offline editing of music and for presentation on an electronic display during performance. In particular, software can show or hide bowings on various notes, according to the performer's needs; it can calculate a full bowing; it can modify a bowing based on preferences indicated by the performer; and it can allow bowings to be archived and searched. This approach is not prescriptive: the performer is in full control of all artistic decisions, while the software carries out repetitive tasks
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